1. Field of the Invention
The present invention relates to a lavatory hopper flushing apparatus capable of automatically flushing lavatory hoppers upon the detection of the use of the lavatory hoppers.
2. Description of the Prior Art
Japanese Patent Publication No. 56-19420 discloses a lavatory hopper flushing apparatus of the above-mentioned type. This known lavatory hopper flushing apparatus comprises a sensor unit for detecting the use of lavatory hoppers, a control unit which operates on the basis of a detection signal given by the sensor unit, and a water supply unit adapted to be actuated by the output signal of the control unit so as to flush the lavatory hoppers. This control unit is designed to regulate appropriately the interval between the detection of the use of the lavatory hoppers and the supply of water for flushing and to ignore detection signals given during the predetermined interval.
This known lavatory hopper flushing apparatus, however, flushes the lavatory hoppers after a predetermined time from the first use of the lavatory hoppers during the predetermined interval, even if the lavatory hoppers are used by a plurality of people during the predetermined interval. Accordingly, the lavatory hoppers become foul and dirty immediately before the termination of the predetermined interval, which is unsanitary and offensive. Furthermore, the lavatory hoppers are not flushed and the sealing water evaporates if the lavatory hoppers are not used for a long time, and hence it is impossible to keep the lavatory hoppers clean.